Displaying 1 result from an estimated 1 matches for "startervalues".
2012 Apr 10
3
nls function
...r function so I did:
fit <- nls(y ~ I(a+b*exp(1)^(-c * x)), data = penetrationks28, start =
list(a=0,b = 1,c=1), trace = T)
The error message I get is:
Error in nls(y ~ I(a + b * exp(1)^(-c * x)), data = penetrationks28, start =
list(a = 0, :
singular gradient
I've tried to change the startervalues but it always gives the same error
I've also tried the following adjustment hoping that the c value would be
negative:
fit <- nls(y ~ I(a+b*exp(1)^(c * x)), data = penetrationks28, start = list(a
= 1,b = 1,c=1), trace = T)
but then the error message is:
Error in nls(y ~ I(a + b * exp(1)^...